This invention relates to a process unit adapted to be removably mounted in a main assembly of an electrostatographic printing machine, the unit comprising a housing and an imaging member inside the housing. The invention further relates to an electrostatographic printing machine employing such a process unit.
Conventionally, in the automatic xerographic process, a latent electrostatic image of an original to be reproduced is recorded upon an image retaining member and the image then made visible, or developed, by means of a finely divided particulate toner material. In reusable xerography, the developed toner image is generally transferred from the image retaining member to a copy sheet, such as paper or the like, and the image affixed thereto to form a permanent record of the original input scene information. Although a preponderance of the toner material comprising the developed image is transferred to the copy sheet, a small amount of residual toner is nevertheless invariably left behind on the image retaining member surface after the transfer operation. In order to restore the image retaining member to conditions suitable for reuse, the residual toner must be cleaned or removed from the image retaining member surface before a new imaging cycle is instituted.